Method of making shirred tubing

ABSTRACT

A method and apparatus are provided for uniformly compressing and compacting a length of flexible, tubular sausage casing into a coherent, shirred casing stick which, from end to end, exhibits circumferential uniformity, is substantially straight and has an uninterrupted, uniform bore.

Dec. 5, 1972 [56] References Cited UNITED STATES PATENTS METHOD OFMAKING SHIRRED TUBING [72] Inventors: Algimantas P. Urbutis, Chicago;

Bernard H. Sehenk, Hinsdale;

26269 47474 /l l 7/7/7 l9l9l. m9 m um u u u e n dwmlnn MCMCM m m mhmBMGCA 5 869 56566 99999 HUN S 88 443 4 78 8 i i i 2496 28 66 i i i i22233 K's mm PM 6 e m H s n mm G m m a 1 Lb M. r a 0 n m C a e .I 0 R M0 r V o h PRF n o :0 M l n JWa U E e n .w S S A H 7 [22] Filed: March 5,I970 Primary Examiner-Lucie H. Laudenslager Appl. No.: 16,651

Attorney-Paul A. Rose, John F. Hohmann and Franklyn Schoenberg RelatedUS. Application Data [62] Division of Ser. No. 765,7ll

[57] ABSTRACT A method and apparatus are provided for uniformlycompressing and compacting a length of flexible, tu-

May 31, i968, abandoned, which is a division of Ser. No. 418,506, Dec.15, 1964, Pat. No. 3,397,069.

bular sausage easing into a coherent, shirred casing stick which, fromend to end, exhibits circumferential uniformity, is substantiallystraight and has an uninterrupted, uniform bore.

14 Claims, 11 Drawing Figures 6 i 2 7M M9 lys s w 4/ i ,6 CP59 2 15 M2IAMZ 7: ll 1' 9 TEA 4 "77 ll 1 U m ."5 m7 MU m m mmm4 WMmZ Tm mU-IP mm 9nm w uam 0 td Uhfi HUN 555 PATENTEDIJEC 1w 3, 704.483

sum 1 or 5 3&

4 38 3 +34 24 c 36 s M i- M /8 25,6 K M flg 'nj'ihgwfl 0 l4 I 3 4 I I a*5! A Q? in IN VENTOQS Alp/Manta: I, Urban: Barnud H. Schmt Joseph J.Risany Wolfe If. Hafiz y 24 T TORNEV PATENTED E 5 I972 3,704,483

sum 3 BF 5 L---- Y Q l q I Bernard h. Schmk l h, Joseph J. Rismy inWalter, V. Marque ATTORNEY PATENTED 5 3,704,483 SHEET l BF 5 INVENTORS.

Alp/mamas I? Urbulis Bernard H- Schenk Joseph J. Risany Walter V.Marbach ATTORNEY PATENTED DEC 5 SHEET 5 0f 5 INVENTORS.

lily/manta: R Urban: Bernard H- Salient Joseph J. Risany Waller V.Marpach 4r romver METHOD OF MAKING SHIRRED TUBING This application is adivision of application Ser. No. 765,711, filed May 3i, 1968, nowabandoned, which was a division of application Ser. No. 418,506 filedDec. 15, 1964, now US. Pat. No. 3,397,069, issued Aug. [3, 1968.

This invention relates to the art of shirring flexible tubular material.More particularly, it relates to the manufacture of flexible tubingshirred and compressed into self-sustaining hollow sticks that areuseful as sausage casings and can be extensively used for the productionof sausages such as frankfurters, pork sausages and the like.

Flexible tubing used for meat casings may be comprised of proteins,carbohydrates, and the like such as collagens, alginates, starches orcellulosic materials such as cellulose esters, cellulose ethers andregenerated cellulose, as well as other natural, synthetic or artificialmaterials.

Regenerated cellulose casings are used extensively in the manufacture ofskinless frankfurters and this invention will be described withparticular reference thereto. In practice, cellulose tubing of anappropriate length such as for example 55 feet, 84 feet, or 110 feet ormore is shirred and then compressed to produce what is commonly termedin the art shirred casing sticks of from about 9 inches to 20 inches inlength. Such casing sticks may be stuffed with meat emulsion by manualor automatic operations. In a manual operation the stick is sheathedonto a thin walled metal stufiing horn connected to a valved vesselfilled with meat emulsion under pressure. The operator controls with onehand the filling and deshirring of the casing and concurrently with theother hand controls the valve and thereby the meat pressure in thestuffing horn to fill the tubing to its proper stuffed diameter.

in an automatic stuffing procedure for making frankfurters, a pluralityof shirred casing sticks may be placed in a dispensing hopper of anautomatic stuffinglinking apparatus for successively dispensing byrolling on its outer surface one stick at a time to clamping means thatalign the stick's bore with a reciprocating thin walled meat stuffinghorn. The automatic apparatus commonly used in frankfurter production,deshirrs the casing by stuffing it with meat emulsion through thestuffing horn, and then links the filled casing so that it may beprocessed as is well known in the art, to produce skinless frankfurters.

For reasons of economy and to speed up the stuffing operation the meatpackers demand a shirred sausage casing in the form of a self-sustainingshirred stick highly compressed in length, that is uniformly straight,and has a large internal hole or bore. End-to-end straightness of thestick and bore is highly desirable to insure the successive dispensingof sticks from a supply loosely piled in a hopper, and transferring thestick to the stuflmg means of an automatic stuffing-linking machine.Durability or coherency of the shirred stick as a self-sustainingarticle is necessary also to insure trouble-free operation with manualand with automatic stuffing apparatus. A large bore in the straightcasing stick permits the use of a large diameter stuffing horn andthereby enables more rapid filling of the casing. More efficientfrankfurter processing operations are in great demand in the industry tooffset increasing labor costs and accordingly, demand highly automatedequipment.

Heretofore shirred casing sticks were provided with a large bore butbecause of the long length of tubing in the shirred sticks (typicalcommercial lengths are 55 feet, 84 feet and 110 feet) the casing sticksdid not always remain straight and on occasion would be disjoined orbroken when removed from a shipping carton for use by the meat packer. Abreak in the stick deshirrs a portion of the casing, causing adiscontinuity in the internal bore resulting in jamming on the automaticequipment and extra handling in the manual operation. in theshirring-compressing operation of manufacturing casing sticks, anyslight nonuniformity such as in wall thickness that may occur in theprocess of manufacturing the cellulosic tubing, is accentuated in thereducing of its length from the unshirred to the shirred compressedstick length such as in the ratio of from about to 1. Some additionalfactors such as moisture in the casing, coloring or striping agents, maycause occasional nonuniformities that make it difficult to maintain theshirred stick in a straight condition after doffing from the shirringmandrel when there is a tendency of the stick to grow in length andbecome bowed. A bowed stick is susceptible to being disjoined or brokenand after breaking is unsuitable for use particularly in automaticstuffing equipment. Also, a bowed stick is not readily handled inautomatic stuffing equipment.

The principal object of this invention is to provide coherentself-sustaining sticks of shirred flexible tubing having an increaseddiameter bore for a specific length and wherein the casing has improvedcoherency against disjoining or breaking and the bore is substantiallystraight from end to end.

Another object of this invention is to provide shirred and compressedcoherent cellulosic sausage casing sticks of improved coherency andstraightness that will readily feed from dispensing hoppers and beeasily sheathed onto the stuffing horns of automatic stuffinglinkingmachines.

Another object of this invention is to provide shirred and compressedcoherent flexible tubing sticks wherein the pleated tubing wall isuniformly helically distributed in its length with respect to asubstantially straight internal bore.

Still another object of this invention is to provide a method forproducing shirred flexible tubing which method yields more uniformdisplacement of the tubing around the mandrel upon which the tubing isshirred.

A further object of this invention is to provide a method of shirringand of interlocking the pleats of the shirred tubing into a uniformspiral superimposed on the normal shirring pleat pattern by coiling andcompacting the tubing fed from the shirring means to thereby yield acoherent self-sustaining substantially straight stick.

A further object of this invention is to provide former and holdbackmeans used in combination with a shirring apparatus and a mandrel forsuperimposing a uniform helical pattern of interlocked tubing pleatsonto the pleat pattern of normal shirred tubing and compacting thetubing into a coherent self-sustaining substantially straight stick.

This invention further provides for a former and holdback passage meanspositioned closely adjacent and centrally aligned with a shirring meansand a floating mandrel adapted to uniformly compact and coil the tubingpleats fed from the shirring means about the mandrel into a spirallyinterlocked pleated tubing wall uniformly distributed in its length withrespect to the mandrel.

Another object of this invention is to provide a shirring apparatus incombination with former and holdback means capable of uniformlyhelically coiling and compacting tubing after it is shirred and whichcombination is readily adaptable to shirr tubings of differentdiameters.

Still another object of this invention is to provide a method of markinga predetermined length of shirred tubing on a mandrel, for severing thepredetermined length from a continuous strand of tubing, the markcomprising a short length of unshirred casing.

Other and further objects will become apparent hereinafter.

According to one embodiment of this invention there is provided anelongate self-sustaining shirred and compressed stick of tubing ofimproved coherency suitable for use as a sausage casing. The coherentshirred tubing is substantially circular in cross section and having asubstantially straight internal bore from its first end to its secondend and a substantially cylindrical exterior surface. In one embodimentthe tubing is shirred by pleating on a mandrel by one of several passageforming shirring methods well known in the art; the shirred tubing isthen compacted and helically spiraled by gathering and coiling theshirred pleats about the mandrel in a uniform spiral pleat patternsuperimposed on the shirred pleat pattern in its passage through anannular spiral former, the pleat pattern of the second end beingannularly displaced from the pleat pattern and at a greater pitch thanthe pleat pattern formed by the shirring passage. In a preferredembodiment, the compacting and spiraling of the shirred pleats in theannular former result in the outer periphery of the pleats beingarranged transverse to the bore.

The shirring of regenerated cellulose casing according to one method ofpracticing this invention is disclosed in Matecki US Pat. No. 2,984,574.The shirring is accomplished by continuously moving the inflated casingby metering rolls from a supply of continuous flattened tubing over amandrel of smaller diameter than the inflated casing to and through agyrating shirring passage of smaller diameter than the inflated casingthe passage being formed by a plurality of shirring rolls where apredetermined length of the casing is shirred as a first step.

The casing in its shirred form is forced forward along the mandrel fromthe shirring passage as a result of the forces of the shirring rollsgripping and folding the inflated casing wall, and in its forwardadvance therefrom is restrained by a closely adjacent compacting meanscomprising an annular former and holdback passage. The annular formerand holdback passage is adapted to resiliently constrictively grip theshirred casings outer wall uniformly and as the shirring forces feed thecasing through the former passage, the helical jaw means compact andhelically displace the shirred casing about the mandrel in its advancethrough the passage as a second step.

When the predetermined length of easing has been shirred and compacted,it is severed from the supply at a mark of unshirred casing as a thirdstep. The mark of unshirred casing indicating the predetermined lengthis provided at the start of a shirring cycle by allowing a portion ofthe casing to be shirred without a holdback or restraining force. Thiscan be done by axially moving the holdback passage along the mandrel inthe direction of the casing movement during this portion of the shirringcycle. The severed casing length is advanced to a mandrel clamp as afourth step.

Additional compaction of the helically coiled casing pleats is impartedto the severed length by axially compressing the casing length on themandrel against the mandrel clamp as a fifth step. In a sixth step thecompressed casing length is doffed from the mandrel to yield aself-sustaining substantially straight casing stick.

This invention also provides apparatus having a floating hollow mandrel;means for supporting the mandrel; means for feeding and shirring apredetermined length of easing onto the mandrel; former and holdbackpassage means for compacting and helically coiling shirred casing aboutthe mandrel; means for marking a predetermined length in a longer lengthof shirred, compacted and coiled casing and means for severing,compressing and dotting the predetermined length of shirred casing fromthe mandrel.

In the embodiment shown in the figures the former and holdback passageis a composite annular structure fixedly mounted central to the shirringpassage closely adjacent thereto and comprised of a plurality of spacedformer jaws, circumferentially equiangularly disposed about the mandrel.The inside surface of each former jaw is curved to a radiusapproximately the radius of the shirred casing exiting from the shirringpassage along the mandrel, and the edge walls of the former jaws inassembly comprise substantially helical grooves, that are spiralledalong the length of the jaws forming the holdback passage. The entryends of the grooves (spaces between the jaws) are each aligned with andare closely adjacent to the mating points of shirring rolls comprisingthe shirring passage. The former jaws are each radially slidablyfastened in the former and holdback structure and are adapted touniformly resiliently constrict the casing in the holdback passage bycommon force means cooperatively urging the jaws toward the mandrel.

The shirred casing is forced from the shirring passage along the mandrelas a result of the shirring forces on the inflated casing and is forcedinto the closely adjacent tapered entry of the cooperating former jawswhich restrain the casings advance, coil and compact the casing pleatsabout the mandrel and may assist in pressing air from the folds of thecasing. In a specific embodiment the mandrel surface in the vicinity ofthe jaws is provided with flats or grooves to vent the air from thecasing folds and thus compact the folds more readily into interlockingpleats.

The helical grooves comprising spaces intermediate the side walls ofmating former jaws, serve as threads which engage continuous ridge-likeportions or bulges normally present in shirred casing exiting from themating points of rolls of a multiroll shirring passage previouslydescribed. As the inside surfaces of the jaws restrain the casingsadvance to constrict and compact a portion of the casing wall the jawsside walls concurrently coil the casing about the mandrel axis todischarge it from the former passage at a speed less than the peripheralspeed of the shirring rolls.

The former and holdback structure is mounted on the machine frame incentral alignment with and closely adjacent to the shirring passage toalign the former jaws with the continuous bulges in casing advanced frommating shirring rolls; to form and compact casing folds into uniformlyinterlocking pleats with a minimum of casing inventory intermediate theshirring and former passages; and also stabilizes the free end of thefloating shirring mandrel against the vibratory forces of the shirringmeans.

The piloting effect that the former or constriction jaws exert upon thecasing's pleated mass in turn stabilize the floating mandrels free endand thereby improves uniformity of shirring particularly with the longcantilever supported mandrels used for shirring lengths of casing suchas 84 feet and I feet.

Compacting the casings wall by the former jaws also compacts theridge-like portions normally present in shirred casing, shaping theridge-like portions into a plurality of spiral crests on the outersurfaces of the shirred casing. Coherency of the casing sticks made bythe instant invention has been improved more than about 50 percent overprior art.

The unifonn disposition of the casing material about the axis of themandrel and of the spiralled surface crests obtained by using theshirring method described, maintains the stick substantially straightafter removal from the mandrel. Straightness of finished casing sticksmade by the instant invention permit the free rolling of a stick underits own weight from rest, down a flat plate sloped at less than 25 tothe horizontal, as compared to the relative immobility of prior artshirred casing sticks under the same test.

Heretofore the severing of the predetermined length of shirred casingwas done manually by deshirring the casing adjacent the shirring passageand locally stressing the deshirred casing wall between gripping meansapplied against the mandrel, while concurrently advancing the shirredcasing length along the mandrel to a compressing station. The shortlength inventory of shirred casing remaining fore of the shirringpassage was not confined by holdback means during the severing operationand tended to deshirr by expanding in length. When the next shirringcycle started to move the inventory of easing against a retractingholdback surface the previous degree of compaction was not reestablishedand the coherency (resistance to breaking) of the prior art compressedsticks was poor, particularly in the area of the inventory.

The annular former and holdback means of the instant invention maintainsthe shirred casing under uniform compaction throughout substantially theentire cycle of shirring; severing and transferring. By providing a markof unshirred casing to designate the predetermined length, severing maybe done remote from the shirring passage as later described. Theholdback passage of this invention is slidably mounted and permitted tomove parallel to the mandrel for a short distance such as about one-halfinch, to advance with the casing only at the start of shirring. Thus fora very brief time interval the shirring forces feeding the casing alongthe mandrel are unopposed and a short length such as about 1 562 inch ofcasing is not effectively shirred thereby providing indicia designatingstart of a shirring cycle. The marked portion of the casing is advancedto a convenient point along the mandrel and the preceding shirred lengthis severed at the mark to be advanced to a compressing station. Casingmade with the method of this invention providing continuous compactionand helical coiling into a uniform pattern after shirring and severingof the length remote from the zone of shirring has improved coherencythroughout the entire length of the stick.

In the drawings:

FIG. 1 is a diagrammatic side elevation of a shirring apparatus, showingthe preferred embodiment of the present invention;

FIG. 2 is a perspective of the upper left hand portion of a shirringapparatus shown in FIG. 1 and showing a mandrel in a central passage ofthe shirring means, and the former and holdback means;

FIG. 3 is a horizontal section taken along the line 3 3 of FIG. 1showing a typical shirring head that may be used with the apparatus ofthe invention;

FIG. 4 is a horizontal section taken along the line 4- 4 of FIG. 1showing the former and holdback passage apparatus;

FIG. 5 is a plan view of a portion of the machine of FIG. 1 showing theformer and holdback passage apparatus;

FIG. 6 is a side elevation of a portion of the machine of FIG. 1 showingthe former and holdback passage in section and means to reciprocate itto and from the shirring head;

FIG. 7 is an enlarged detail elevation of the former jaws;

FIG. 8 is an end elevation taken along line 88 of FIG. '7;

FIG. 9 is an enlarged perspective of the former jaws and holdbackpassage juxtaposed about the shirred casing on a portion of the mandrel;

FIG. 10 is a side elevation of a casing stick of the invention;

FIG. 11 is an enlarged transverse section of the easing stick takenalong the line 11-11 of FIG. 10.

As may be seen from FIG. 1 in the operation of the shirring machine asupply of flattened tubing such as cellulosic tubing 18 isintermittently withdrawn from a supply reel 14. The flattened tubing 18is expanded as by gaseous means and advanced through a pair of verticalguide rolls 25 to metering rolls l6 and the metered inflated tubing 20is aligned centrally by two pairs of annularly grooved rolls 19 arrangedin tandem, which guide the tubing onto hollow mandrel 12 and throughshirring head S.

The desired length of inflated casing 20 is loosely shirred by any of anumber of suitable shirring heads S mounted on machine frame 10, amongwhich for example are those as shown in FIGS. 2 and 3 and described inMatecki U.S. Pat. Nos. 3,097,393, 2,983,949 and 2,984,574. In a specificembodiment shirring head S typically such as is disclosed in MateckiU.S. Pat. No. 2,984,574 and as may be seen from FIG. 3 is comprised of aface plate 44 mounting angle gear box units 42, 42', 42" andinterconnected to drive cogged shirring rolls 40, 40', 40" at the samespeed and direction. The annularly grooved cogged rolls 40, 40', 40" arealigned to provide a shirring passage centered on mandrel 12. in thearrangement shown, roll 40 centerline is aligned with a 6 oclock axis,roll 40' with a oclock axis and roll 40" with a 2 o'clock axis. Matingpoints 41, 41', 41" of the rolls beveled surfaces occur at 12 o clock, 4oclock and 8 oclock axes. In shirring inflated casing with thethree-roll shirring head slight bulges 26, 26', 26" normally occur inthe cylindrical outer surface of the shirred casing that are alignedwith the mating points of the rolls These bulges are herein referred toas ridge-like portions of the shirred casing outer wall.

The loosely shirred casing 21 is restrained in its ad vance from theshirring head S by a former and holdback passage shown generally as H inFIGS. 1 and 2. The former and holdback means which is later described indetail, compacts the loosely shirred casing length by coiling andinterlocking the pleats and folds of the shirring in a uniform spiralend to end about the mandrel surface 12 and compacts the bulges into aplurality of spiral crests 27, 27, 27" that may be seen in FIGS. 10 and11. it is believed that the crests 27, 27, 27" additionally serve tostiffen the compacted casing stick and improve its coherency.

The leading end of the floating hollow mandrel 12 has a tip 24positioned between the shirred head S and the nip of the metering rollsl6. Gaseous inflating means is supplied to the casing through tip 24 ofmandrel 12 which is supported in stationary position by clamps C, K. Theinflating air is supplied to the mandrel 12 through first clamp Cconnected to a compressed air supply hose 38.

The compacted shirred casing length 22 is severed from the previouslycompacted shirred casing length 22 at a mark of unshirred casing 28 madeat the start ofa shirring cycle by means later described, clamp C isopened and the severed casing length 22' is advanced along mandrel [2until its fore end abuts closed clamp K. Compressor arm 30 is rotatablyfixed on piston rod 36. A pair of mandrel encircling jaws 32 are mountedon the outboard end of compressor arm 30 to engage mandrel l2 aft of thesevered casing. Pneumatic cylinder 34 is actuated thereby advancingpiston rod 36 and compressing the severed casing length 23 against clampK. The cylinder 34 is released, thereby retracting compressor arm 30 andconcurrently lifting it from mandrel 12. Clamp C is closed, clamp K isopened and the compressed casing length 23 is doffed from the end ofmandrel 12.

Meantime the next shirring cycle provides a next sue ccssive length ofcompacted casing 22 and the operation of severing, transferring,compressing and doffing of the stick ofcasing is repeated.

Refer now to FIGS. 4,5, and 6. The former and holdback structure H ismounted to machine frame 10 by angle bracket 46. Adjacent the upper endof bracket 46 is horizontally mounted a pair of slide rods 48, 48cantilevered from bracket 46 toward the shirring passage, and spacedequidistant about the vertical center line of mandrel 12. The slide rods48,48 in combination comprise slide ways l'or elongate parallel ballbushings 52, 52' pressed into carriage block 50, on the top surface ofwhich is horizontally fastened the holdback mounting sleeve 54 centeredon mandrel 12. Mounting sleeve 54 has equiangularly spaced grooves 56,56, 56" iongitudinally aligned with mandrel 12, the grooves beingarranged about the inner surface of sleeve 54 at the 12 oclock, 4o'clock and 8 oclock axes, and which are also aligned with mating points41, 41', 41" of the shirring rolls 40, 40', 40".

Refer now to FIGS. 7, 8, and 9. Three identical former jaws 60, 60', 60"have tongues 58, 58', 58" each tongue being machined for a slide fit ingrooves 56, 56', 56" The former jaws as seen in FIG. 7 are representedas being in normal assembly in mounting sleeve 54. Former jaws 60, 60',60 have a casing entry end having a conical pilot surface 64. Theinternal cas ing compacting surface 66 is cylindrical and is machined toa diameter approximating the external diameter of shirred casing 21 suchas about 1 inch diameter for a code 26 casing. The former jaws innersurface 66 may be made of metal such as steel or of any material capableof maintaining a smooth, polished, shaped surface without abrading thecasing passing therethrough. The axial edges 68, 68', 68" of the formerjaws are machined to be spaced apart about three-sixteenth to one-fourthinch at an angle of about from 20 to 25 to the mandrel l2 axis, toprovide substantially helical grooves 70, 70', 70". Grooves 70, 70', 70"are arranged to engage the bulges or ridge-like portions of the casingwall occuring at the exit of the shirring passage and thereby axiallydisplace the bulges and coil the casing about the mandrel as it isforced through the forming passage. The constricting pressure of thejaws form the shirred easing into a helically interlocked pleatedstructure and concurrently the jaw edges comprising grooves 70, 70', 70"also compress the bulges into more compact crests 27, 27', 27" which maybe seen in FIGS. 10 and 11.

Refer again to FIG. 6 where it may be seen that the jaws tongues 58,58', 58" are slideably fastened into the grooves 56, 56', 56" of sleeve54 by end thrust plate 74 Cap screws 72, 72', 72" fastened to tongues58, 58, 58" resiliently urge the tongues outwardly from mandrel 12 bycompression spring means 73, 73, 73". Single acting air cylinders 75,75', 75" are radially fastened in sleeve 54 centered on grooves 56, 56,56". Piston rods of the air cylinders are arranged to abut the innersurface of grooves 56, 56', 56". The air cylinders are commonly actuatedby means later described. When pressurized, such as to about 35 to 50pounds per square inch air pressure to provide about 15 to 22 pounds offorce, the pistons of the air cylinders 75, 75, 75" engage the topsurfaces of tongues 58, 58', 58 to urge the jaws inwardly toward mandrel12 thereby constricting internal compaction surfaces 56, 56' 56" aboutthe casing 21 advanced along mandrel 12 by the rotative force ofshirring rolls 40, 40, 40".

The constriction forces applied to the outer surface of casing 21 by thethree jaws determines the degree of compaction and restraint the shirredcasing exerts against the shirring forces and the resulting forming ofthe shirred easing into a helically spiralled shirred stick. The casingbulges advanced into the spaces comprising grooves 70, 70, 70 are notimmediately compacted but contact the jaw edges 68, 68, 68" and actsimilar to the threading of a long lead multiple thread bolt into amating nut, to coil the pleats concurrently as they are nested togetherin the former passage. As the compacted shirred casing passes throughthe former jaws, the bulges are formed into spiralled crests 27, 27',27" resulting in a stiff interlocked pleated casing.

Refer again to FIGS. 1 and 2. The air cylinders 75, 75, 75" are commonlyconnected by pipe 76 to air pressure regulating means 78. Adjustment ofregulator means 78 provides a uniform adjustable compacting force on thecasing which controls the degree of compaction that may be obtainedbetween the former jaws and the shirring passage. A uniform force offrom about to pounds on each of the jaws has been found desirable toachieve the desired compaction of the shirred casing. A bypass air valve79 is provided to release pressure on the jaws when it is necessary, andretract them from mandrel 12 to restring casing onto the mandrel 12.

Air cylinder 80 is horizontally mounted on bracket 46 in verticalalignment with mandrel 12. Air cylinder 80 is connected by supply pipe82 through solenoid operated air valve 83 to a source of compressed air.When valve 83 is opened through an appropriate electrical signal,cylinder 80 is pressurized and piston rod 81 is extended about one-halfinch from bracket 46 to abut the end surface of carriage 50 and advanceit on slide ways 48, 48' to normal operative position closely adjacentthe shirring passage.

Cylinder 80 is pressurized for the greater part of the shirring cycle tomaintain the former passage adjacent the shirring passage. When shirringstops and clamp C is opened, the air pressure on cylinder 80 isreleased. For a brief time interval at the start of shirring, cylinder80 is not pressurized, thereby permitting the holdback jaw assembly oncarriage 50 to be moved on the slide ways 48 by the shirring forcesexerted on loosely shirred casing 21, until carriage 50 is arrested byabutment with bracket 46.

Thus for the brief time interval noted, the shirred casing 21 is fedfrom the shirring passage against substantially less then normalholdback restraining force, and a length of about I 1% inches of casingis not normally nor regularly shirred against the former and holdbackmeans. Air pressure is reestablished after several seconds of shirringand carriage 50 is returned to normal operating position adjacent theshirring passage thereby maintaining substantially uniform compaction incasing 22. The abnormally or irregularly shirred length of easingresulting from the momentary concurrent advancing carriage and easingmovement provides distinctive visual indicia 28 of the desiredpredetermined length of shirred, compacted casing 22 and permits thesevering step to be done at a point remote from the shirring passage.

in the operation of the shirring machine the supply of continuous casingtubing 18 may have occasionally occuring faults such as tubing breaks,tubing couplers or splices that require halting the shirring, removal ofthe faulty tubing and a restringing of a fresh supply of tubing. Inorder to maintain the normal compaction of the previously shirredcompacted length 22, it is desirable to remove the faulty tubing and aslittle as possible of the shirred casing 2|. A pointed brass pick 85 isprovided in a unit mounted adjacent the shirring passage to easilyrestrain the shirred casing 21 advanced therefrom and sever the shirredcasings trailing end against mandrel 12 while the faulty tubing isremoved from the machine.

Bracket 86 fastened to machine frame 10, is provided with slide sleeve87 diagonally aligned with mandrel l2. Conical pick 85 is preferablybrass and is fastened to a shoulder 89 on one end of rod 88, that isslidably mounted in slide sleeve 87. Rod 88 is urged upwardly bycompression spring 89 to abut shoulder 89 with the lower end surface ofslide sleeve 87 and thereby normally maintain pick point out ofengagement with shirred casing 21. Knob 91 on the upper end of rod 88 isused to manually depress the pick point into engagement with mandrel 12while faulty tubing is severed and removed from the machine.

The former or holdback means of the invention is preferably arranged andadjusted in combination with a shirring means and a mandrel; tosuperimpose on a normal shirred casing a uniformly spiralled interlockedpattern of pleats concurrently compacted to a length of from aboutone-thirtieth to one-fiftieth of its unshirred length and axially coiledabout the mandrel at least from 2 to 8 or more degrees of revolution perone foot of unshirred length.

The invention may be employed in connection with shirring; compactingand coiling; and compressing cellulose sausage casings of varyingdiameters and wall thicknesses. It is particularly useful in connectionwith casings ranging in diameter from nine-sixteenth inch to 1% inchesand having wall thickness of from about 0.0006 or less to 0.003 inch ormore.

Several actual forms of apparatus according to the invention wereconstructed and operated by means of the three-jaw apparatus illustratedin FIGS. 1 to It to shirr easing of 0.84 inch inflated diameter at therate of about 700 feet per minute of easing length, said casing beingshirred with a three-roll arrangement of cogged rolls shaped accordingto the teachings of Matecki U.S. Pat. No. 2,983,949 and a three-jawholdback of the fol lowing specifications:

Inflated casing diameter 0.840 inch Jaw length about 16/4 inch Diameterofjaw inner surface 3 H32 inch Space between jaws in normal assemblyabout H32 inch Mandrel diameter in shirring passage .620 inch in formerpassage .580 inch Angle of coiling groove to the mandrel axis about 22Pounds force applied to each jaw about l7 to 20 lbs.

In repeated operations 84 foot lengths of 0.84 inch inflated diametercasing supply were shirred on a 0.620 inch diameter mandrel andcompacted to a length of about 24 inches concurrently while the shirringpleats at the fore end of the compacted casing lengths were uniformlycoiled more than 550 of revolution about the mandrel with respect toshirring pleats at the aft end of the casing lengths; and the casing wascompressed to a length of about 14 inches. A typical 84 foot casingstick may be seen in FIG. 10.

These 84 foot casing sticks of 0.84 inch inflated diameter casing weretested and found to be ofa cylindrical straightness such that they wouldroll from rest under their own weight, down a flat metal plate sloped atan angle of 25 to the horizontal. Routine testing of easing sticks madeby the instant invention demonstrated that consistent coherency of thesticks (re' sistance to disjoining or breaking) when tested by thefollowing coherency test method was within a range of 3.0 to 4.0inch-lbs. force.

Prior art shirred casing sticks, that were shirred and compressed by thesame method as herein described,

but not compacted by passing and forming through a former and holdbackmeans herein described, had a coherency of from L8 to 2.5 inch-lbs.force.

COHERENCY TEST METHQD Coherence of a casing stick is determined bymeasuring the force required to break a 2% inch unsupported extension ofthe shirred stick on a polished steel rod of seven-sixteenth inchdiameter which is cantilevered to a wooden test stand. The test stick iscut at a point 2 inches from its fore end and the short lengthdiscarded. The longer section is then deshirred 2% inches at the cutend, and a 3 inch length of -74 inch wide pressure sensitive tape(Permacel No. l0004) is applied over the 2-1/2 inch deshirred tab andthe last one-half inch of shirred stick. Then the taped stick ispositioned on the steel rod against a reference marker which allows a 2/4 inch extension of the casing stick to project beyond the rod end. Aforce gauge (such as Hunter Force Indicator, Model L-IM with a Hold atMaximum Device) is fastened to the tape-supported tab by means of aspring loaded jaw, and the tab is slowly pulled down until the stickbreaks. The force reading is noted, and the actual length of the brokensection is measured to the nearest 0.1 inch. The product of the force inpounds multipled by the length in inches is reported as coherence ininch-pounds offorce.

It will be obvious to those skilled in the art that the relative motionof the casing about the mandrel can be obtained by other means such asrotating the former jaws about the mandrel, taking into considerationthe desired rate of rotation of the jaws about the mandrel, the angularspacing of the jaws from each other, and the pressure exerted by thejaws against the shirred casmg.

Another method of imposing a helical pattern about a shirred pleatpattern is to impart rotating motion to the mandrel with respect to theshirring passage; and preferably rotating and concurrently retractingthe mandrel in the shirring passage.

Since it is obvious that various changes can modifications may be madein the above description without departing from the nature or spiritthereof, this invention is not restricted thereto except as set forth inthe appended claims.

What is claimed is:

1. In a method of forming a shirred tubing into a coherentself-sustaining shirred stick the step which comprises passing a shirredtubing advancing from a shirring passage through an annular restrainingpassage about a mandrel approximately equal to the external diameter ofthe shirred casing.

2. in a method of forming shirred tubing into a coherent self-sustainingstick the steps which comprise advancing the shirred tubing from theshirring passage and then coiling and compacting the shirred tubingabout a mandrel to uniformly spiral the tubing in its length.

3. In a method of forming shirred tubing into a coherent self-sustainingstick the steps which comprise advancing the shirred tubing from theshirring passage and then concurrently coiling and compacting theshirred tubing about a mandrel to uniformly spiral the tubing in itslength.

4. In a method of forming shirred tubing into a coherent self-sustainingstick having a bore and a substantially cylindrical outer surfacewherein the tubing is shirred in a predetermined pleat pattern, the stepwhich comprises helically displacing the shirred pleats in a helicalpattern greater than and superimposed on the shirred tubing pleatpattern.

5. In a method of forming shirred tubing into a coherent self-sustainingstick having a bore and a substantially cylindrical outer surfacewherein the tubing is shirred in a predetermined pleat pattern, the stepwhich comprises subjecting the shirred pleats to a restraining force onthe pleats outer surface to helically displace the shirred pleats in ahelical pattern greater than and superimposed on the shirred tubingpleat pattern.

6. In a method of forming shirred tubing into a coherent self-sustainingstick having a bore and a substantially cylindrical outer surfacewherein the tubing is shirred in a predetermined pleat pattern, the stepwhich comprises subjecting the shirred pleats to a rotating force on thepleats bore surface to helically displace the shirred pleats in ahelical pattern greater than and superimposed on the shirred tubingpleat pattern.

7. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred, advancing the shirred tubing from theshirring passage and then uniformly coiling and compacting the shirredtubing about the mandrel to uniformly spiral the tubing in its length.

8. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred, advancing the shirred tubing from theshirring passage and then uniformly coiling and concurrently compactingthe shirred tubing about the mandrel to uniformly spiral the tubing inits length.

9. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred into a predetermined pattern and uniformlycoiling and compacting the shirred tubing about the mandrel to uniformlyspiral the tubing in its length and helically displacing the shirredpleats in a helical pattern greater than and superimposed on the shirredtubing pleat pattern.

10. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred into a predetermined pattern, subjecting theshirred pleats to a restraining force imposed on the pleats outersurface to compact and helically displace said pleats in a helicalpattern greater than and superimposed on the ordered repeated shirredpattern of pleats.

11. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred into a predetermined pattern. subject ingthe shirred pleats to a restraining force imposed on the pleats outersurface to compact and helically displace said pleats in a helicalpattern greater than and superimposed on the ordered repeated shirredpattern of pleats, the outer periphery of said pleats beingsubstantially transverse to the bore.

12. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises feeding a shirred tubing ofpredetermined length advancing from a shirring passage through a formerand holdback passage cooperatively positioned about a mandrel to compactthe shirred tubing about the mandrel and uniformly spiral the tubing inits length.

13. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises feeding a shirred tubing ofpredetermined length advancing from a shirring passage through a formerand holdback passage cooperatively positioned about a mandrel toconcurrently compact the shirred tubing about the mandrel and uniformlyspiral the tubing in its length.

14. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises feeding a predetermined length oftubing shirred into a predetermined pleat pattern through a former andholdback passage about a mandrel to compact the shirred tubing about themandrel and uniformly spiral the tubing in its length displacing theshirred pleats in a helical pattern greater than and superimposed'on theshirred tubing pleat pattern.

It l II I i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3,7 5 Dated December 5, 1972 Algimantas P. Urbutis et a1.

Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Claim 1, column 11, line 5 after "mandrel" insert said annular passagebeing Claim 1, column 11, line 55, delete "casing" and insert therefortubing En'gncd and Sealed this xixreemh Day of August I977 [SEAL]Arrest:

RUTH C. MASON C. MARSHALL DANN Arres ing Off Commissioner of Patents andTrademarks

1. In a method of forming a shirred tubing into a coherentselfsustaining shirred stick the step which comprises passing a shirredtubing advancing from a shirring passage through an annular restrainingpassage about a mandrel approximately equal to the external diameter ofthe shirred casing.
 2. In a method of forming shirred tubing into acoherent self-sustaining stick the steps which comprise advancing theshirred tubing from the shirring passage and then coiling and compactingthe shirred tubing about a mandrel to uniformly spiral the tubing in itslength.
 3. In a method of forming shirred tubing into a coherentself-sustaining stick the steps which comprise advancing the shirredtubing from the shirring passage and then concurrently coiling andcompacting the shirred tubing about a mandrel to uniformly spiral thetubing in its length.
 4. In a method of forming shirred tubing into acoherent self-sustaining stick having a bore and a substantiallycylindrical outer surface wherein the tubing is shirred in apredetermined pleat pattern, the step which comprises helicallydisplacing the shirred pleats in a helical pattern greater than andsuperimposed on the shirred tubing pleat pattern.
 5. In a method offorming shirred tubing into a coherent self-sustaining stick having abore and a substantially cylindrical outer surface wherein the tubing isshirred in a predetermined pleat pattern, the step which comprisessubjecting the shirred pleats to a restraining force on the pleats outersurface to helically displace the shirred pleats in a helical patterngreater than and superimposed on the shirred tubing pleat pattern.
 6. Ina method of forming shirred tubing into a coherent self-sustaining stickhaving a bore and a substantially cylindrical outer surface wherein thetubing is shirred in a predetermined pleat pattern, the step whichcomprises subjecting the shirred pleats to a rotating force on thepleats bore surface to helically displace the shirred pleats in ahelical pattern greater than and superimposed on the shirred tubingpleat pattern.
 7. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred, advancing the shirred tubing from theshirring passage and then uniformly coiling and compacting the shirredtubing about the mandrel to uniformly spiral the tubing in its length.8. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred, advancing the shirred tubing from theshirring passage and then uniformly coiling and concurrently compactingthe shirred tubing about the mandrel to uniformly spiral the tubing inits length.
 9. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises moving a predetermined length oftubing concentrically over a mandrel to and through a shirring passagewhere the tubing is shirred into a predetermined pattern and uniformlycoiling and compacting the shirred tubing about the mandrel to uniformlyspiral the tubing in its length and helically displacing the shirredpleats in a helical pattern greater than and superimposed on the shirredtubing pleat pattern.
 10. The method of shirring flexible tubing into acoherent self-sustaining stick which comprises moving a predeterminedlength of tubing concentrically over a mandrel to and through a shirringpassage where the tubing is shirred into a predetermined pattern,subjecting the shirred pleats to a restraining force imposed on thepleat''s outer surface to compact and helically displace said pleats ina helical pattern greater than and superimposed on the ordered repeatedshirred pattern of pleats.
 11. The method of shirring flexible tubinginto a coherent self-sustaining stick which comprises moving apredetermined length of tubing concentrically over a mandrel to andthrough a shirring passage where the tubing is shirred into apredetermined pattern, subjecting the shirred pleats to a restrainingforce imposed on the pleat''s outer surface to compact and helicallydisplace said pleats in a helical pattern greater than and superimposedon the ordered repeated shirred pattern of pleats, the outer peripheryof said pleats being substantially transverse to the bore.
 12. Themethod of shirring flexible tubing into a coherent self-sustaining stickwhich comprises feeding a shirred tubing of predetermined lengthadvancing from a shirring passage through a former and holdback passagecooperatively positioned about a mandrel to compact the shirred tubingabout the mandrel and uniformly spiral the tubing in its length.
 13. Themethod of shirring flexible tubing into a coherent self-sustaining stickwhich comprises feeding a shirred tubing of predetermined lengthadvancing from a shirring passage through a former and holdback passagecooperatively positioned about a mandrel to concurrently compact theshirred tubing about the mandrel and uniformly spiral the tubing in itslength.
 14. The method of shirring flexible tubing into a coherentself-sustaining stick which comprises feeding a predetermined length oftubing shirred into a predetermined pleat pattern through a former andholdback passage about a mandrel to compact the shirred tubing about themandrel and uniformly spiral the tubing in its length displacing theshirred pleats in a helical pattern greater than and superimposed on theshirred tubing pleat pattern.